I have had my 98.5 for about a year and never liked the towing performance - always slowed down on hills and couldn't keep speed (70mph would turn into a straining 60 mph). Partly for need and partly for the cool factor, I added:

Afe stage 1 intake
MBRP 4" exhaust
HTT manifold
Van Aaken box

What a difference! I can keep speed - I can sit at 70 mph...up a hill...not downshift to 4th......this is towing! Much better and EGTs never went over 900 - 950 degrees on a 2000 mile trip from TX to GA.

Mileage improved from stock - 10 mpg to 11.7 average (at 70-74 mph).

Would injectors change mileage at all?

Thanks for the advice I received here.

 

A set of 275 injectors would be perfect.

 

Injectors would be a good upgrade. Should improve mileage, how much is debatable. RV275(40-50)hp, or Mach 1.6s(90 hp) or EDGE Jammer IIs(75hp or IIIs 100hp) would be good choices.

However, with injectors, you will need a South Bend Con O clutch

Just ordered the OFE and Mach 1.6s for mine. Can't wait to see the difference there.

 

I run the VA/275 combo on a stock clutch with no problems.

 

Are you sure he can run 100 Horse injectors and still tow up hills and what not. I would think the EGT's would get too high.

 

I have the VA and 275's, and it is perfect for towing. Plenty of power but still reasonable for the drivetrain. I am very happy with the combo. My mileage has also come up when empty, and is about the same loaded.

 

I think EGT's would be fine with Mach II's and the VA. Remember the only fuel being added is from the injectors. My II's did fine with a 27' camper going from TX to MO. My EGT's only got up to 1100 in a hard pull. (That is with a stright pipe stock exhaust) I dont see a timing box putting this much higher. The only issue is the new power gives the ability to lug the engine more.......which is where EGT's will climb....just watch your gauge and you will be fine.

NOW for the clutch....anything more stacked on my II's needs a clutch. I can brake it loose at will. I dont think the RV 275's with a VA would be that big of a deal (40 HP) BUT anything over 75HP....may look into it......

 

Welcome to the world of ... through more power!

I'm with Big Blue on this one. Bosch 275's will make a nice difference, usually aid mileage, are inexpensive and will let you keep stock clutch... if not towing real heavy?

But...if you have the funds, Mach 1.6's and a new clutch would be the perfect towing combo to add to your present set up! These additions would change ... into

RJ

 

The mach 1.6's and the stock clutch probably won't get along to well if your pulling heavy loads. You shouldn't have any problems with EGT's either.

 

If you're going to change injectors, go with the MACH 1.6's. Clutch won't like it much though, you'll need to upgrade. I do lots of towing GVCW 18,500lbs with my mods, and no issues with egt's either.

 

Mach 1.6s are the way to go I have no problem keeping egts under control .only the steepest grade and real heavy load will run egts to 1300*and thats real rare 1200* I see alot but boy am i movin
I also have a 01 SO 5spd with Rv275s and a smarty and my EGTs run just as hot as the 01 HO 6spd with catcher and mach 1.6s. and the 2 trucks are like nite and day!

heavyest load to date just under 30K

 

i have a friend that used to have a va and the old 1.5s and it was a sweet set up for pulling the stock clucth was ok for awhile till he got a wild hair and tried sled pulling then it was all over for that clutch .

 

I am curious why this is bad towing performance? I would say thats excellent, depending on the weight you are pulling, if you ONLY drop 10mph's pulling a hill. Step into the past 10-15years. The days of the 454's, 460's, and the 440's. Then you would have something to complain about when you come to a hill and your speed gets cut in half.

 

Good point, RJF.


It's all relative.

Guys who complain about dropping to 60mph on a hill have never had the pleasure of crawling up a hill in granny low at 5mph for 30 minutes

 

I recently put the rv 275's in, and I highly recommend them for towing. I didn't see an increase in egts. Light throttle response is much improved.